Here is the full list of all 26 SUPERHOT achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Beat all Challenges.
Get RED ending in every level of SPEEDRUNrt challenge.
Find all secrets.
Kill over 1987 Red Dudes in endless mode.
Kill 3 Red Dudes with one shotgun shot.
Get RED ending in every level of SPEEDRUN challenge.
Unlock all endless levels.
Launch every app in the system.
Kill 100 Red Dudes with a katana.
Kill 100 Red Dudes with a rifle.
Become part of the community.
Kill 100 Red Dudes using melee.
Kill 3 Red Dudes with one rifle burst.
Kill 2 Red Dudes with one katana throw.
Complete the game.
Kill 100 Red Dudes with a shotgun.
Cut bullet with a katana.
Kill an enemy by jumping on him.
Get back to the system after being expelled.
Score 100 headshots.
Kill 100 Red Dudes with a pistol.
Complete SERV level.
Shoot down a bullet with a bullet.
Upload a replay on killstagram.com
Complete SUBWAY level.